At the VON Conference in Boston, Microsoft introduced an early beta of "Istanbul," a next generation messaging client that will integrate with Live Communications Server (LCS) 2005. Istanbul not only enables IM, VOIP, video and Web conferencing, but also works with current PBX telephony systems.

Istanbul brings to fruition Microsoft's longstanding plans to tightly integrate real-time communications with Office. BetaNews first reported on the company's intentions in October 2002, which included scheduled multi-party audio and video and data collaboration, as well as extended access to mobile devices.

The first milestone on the roadmap was the current Live Communications Server 2003, known by the code-name Greenwich. LCS 2005, which is presently in release candidate phase, comprises version 2 of Greenwich. Istanbul fills in the missing piece of the puzzle, and ties together LCS's disparate messaging capabilities under a familiar IM client interface.

A Microsoft spokesperson explained the product's role to BetaNews: "The relationship between Istanbul and LCS is similar to that between Exchange and Outlook. LCS is the enterprise grade server and Istanbul is the enterprise client software."

"Istanbul is yet another Microsoft effort to pull technologies into Office and so extend the suite's utility," Jupiter Research senior analyst Joe Wilcox told BetaNews. "Remember that address book, calendar and e-mail features existed in separate products before Microsoft brought them into Office through Outlook, which hooked into Exchange Server. Istanbul will bring IM, telephony and identity services into Office, but, again, connected to a server product."

In order to appeal to a broad range of enterprise customers, Istanbul goes beyond voice over IP (VOIP) to incorporate its messaging capabilities with established telephony systems.

"Companies could install the server and client software to work with their existing PBX and PSTN phone systems or as part of new voice over IP deployments, explained Wilcox. "So, from the IM client, a user would either be able to extend availability through call roaming or check a coworker's availability, going so far as to call right from the messenger."

With the upcoming "Connectivity Pack," Microsoft says Istanbul will also interoperate with AOL Instant Messenger, Yahoo! Messenger and the company's own MSN Messenger.

Although Istanbul will replace Windows Messenger as the preferred client for real-time communications, Microsoft will continue to ship the older client with Windows.

"Istanbul won't be right for every customer," explained Wilcox. "Many businesses won't want the level of integration with Office, IM and telephony or to pay to add additional server products. So, it would make sense for Microsoft to continue advancing Windows Messenger development."

Istanbul is set for a final release in the first half of 2005, but organizations can nominate themselves for the beta program by contacting their Microsoft sales representative.